Materials applicable for dental impression are well known in the art.
Commonly used classes of impression materials are based on addition- or condensation crosslinking-reactions of polyorganosiloxane containing components as described e.g. in U.S. Pat. No. 5,064,891, EP 0 729 341 A1 or U.S. Pat. No. 4,657,959 or on crosslinkable polyethers, e.g. so-called azridino-polyethers as described e.g. in EP 1 210 055 B1.
Recently, hybride materials of polyorganosiloxanes and polyether as described e.g. in EP 1 290 998 A1 and DE 19719438 B4, are available.
The mentioned materials typically possess a variety of properties including a quick setting behaviour and a good dimensional stability. Generally, the materials are provided in two components to be mixed prior to use.
Besides the curing mechanism, impression materials can be classified according to their consistencies (ISO 4823) as putty materials (type 0, consistency ≦35 mm), heavy-bodied materials (type 1, consistency ≦35 mm), medium-bodied (type 2, consistency=31-41 mm) and light-bodied (type 3, consistency ≧36 mm). Among those, putty type impression materials are widely used as tray materials.
Addition or condensation cured silicone impression materials which contain C8-C24 Isoparafin are described in EP 0219660 A2.
U.S. Pat. No. 4,879,339 describes an addition cured silicone composition with putty consistency comprising apart from vinyl-functionalized organopolysiloxanes, a crosslinker, Pt-catalyst and filler, a paraffin oil and an antioxidant. Herein the paraffin oil is used to adjust the handling properties of the putty, whereas the antioxidant ensures the stability of the aliphatic component.
The use of paraffin-loaded fillers in dental silicone-based impression materials is described in DE 3406233A 1. The preloading of the filler prevents sweating of paraffin oil from the pastes and the cured product.
EP 1 083 860 B1 describes very high viscous impression materials containing a QM resin and a vinyl-terminated polydimethylsiloxane with a molecular weight of 400000 to 500000 g/mol which makes the material non-sweating.
U.S. Pat. No. 6,838,499 B2 describes a curable composition which includes elastomer powder and is tack-free and easy to work. According to the description it can comprise a dihydroxy-functionalized silicone oil with a viscosity of up to 1,000,000 mPa*s for condensation curable putty formulations or a divinylterminated silicone oil with a viscosity of up to 10,000,000 mPa*s for addition cured silicone compositions although no examples are given.
U.S. Pat. No. 5,066,714 describes a curable organopolysiloxane putty-like composition which comprises apart from divinylpolysiloxanes, crosslinker, catalyst and filler an organopolysiloxane with at least to different alkyl substituents as release agent.
EP 0 398 745 B1 describes a curable silicone composition a hydrophlized addition-cured silicone impression material which might contain a vinyl-terminated organopolysiloxane with a viscosity of up to 5,000,000 mPa*s.
Recently, also automix putty materials have been made available as e.g. described in EP 1 372 575 B1 or EP 1 353 625 B1.